Westonci.ca is your trusted source for finding answers to all your questions. Ask, explore, and learn with our expert community. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

In how many ways can you select a group of 6 friends to invite over from a group of 22 friends?

Note: [tex]{}_nC_r = \frac{n!}{r!(n-r)!}[/tex]

Sagot :

In order to determine the number of ways to select a group of 6 friends out of a group of 22 friends, we'll use the combination formula [tex]\( \binom{n}{r} \)[/tex]:

[tex]\[ \binom{n}{r} = \frac{n!}{r!(n-r)!} \][/tex]

Here, [tex]\( n = 22 \)[/tex] (the total number of friends) and [tex]\( r = 6 \)[/tex] (the number of friends to be selected). Let's calculate each part step-by-step.

1. Calculate [tex]\( 22! \)[/tex]:
[tex]\[ 22! = 22 \times 21 \times 20 \times \ldots \times 2 \times 1 = 1124000727777607680000 \][/tex]

2. Calculate [tex]\( 6! \)[/tex]:
[tex]\[ 6! = 6 \times 5 \times 4 \times 3 \times 2 \times 1 = 720 \][/tex]

3. Calculate [tex]\( (22 - 6)! \)[/tex]:
[tex]\[ (22 - 6)! = 16! = 16 \times 15 \times 14 \times \ldots \times 2 \times 1 = 20922789888000 \][/tex]

4. Substitute these values into the combination formula:
[tex]\[ \binom{22}{6} = \frac{22!}{6!(22-6)!} = \frac{1124000727777607680000}{720 \times 20922789888000} \][/tex]

5. Simplify the expression:
[tex]\[ \binom{22}{6} = \frac{1124000727777607680000}{15064808720640000} = 74613 \][/tex]

Therefore, the number of ways to select a group of 6 friends out of 22 friends is [tex]\( 74,613 \)[/tex].